The invention relates generally to systems and methods for processing complex biological materials into subcomponents.
Many conventional blood cell isolation procedures require preliminary red blood cell depletion and sample volume reduction. These are commonly required processing steps for long-term cell banking and regenerative medicine applications where a maximal yield of rare cells is desired in a reduced volume due to storage limitations and/or the small volume requirements needed for direct transplantation. Today, the most common techniques for processing blood-cell containing samples (e.g. cord blood, bone marrow, peripheral blood) involve density-gradient sedimentation using centrifugation with or without the use of a density-gradient media to improve separations. Automated centrifugal systems have recently been developed for closed-system processing of cord blood and bone marrow samples in order to meet the growing needs for high-throughput sample processing. While greatly improving throughput compared to manual techniques, centrifugation-based devices have limited flexibility and portability due to the weight and fixed physical dimensions of the centrifuge bucket.
Filtration techniques are also used in a number of blood cell separation applications. For example, depth filtration has been used for sometime to achieve removal of leukocytes from whole blood (e.g. for transfusion applications). However these filters are designed for maximal leukocyte depletion (via trapping of cells within the filter) and have not been designed for high cell recovery following the filtration step. In addition, membrane-based plasmapheresis is a common technique for removal and processing of plasma from whole blood. However, these techniques do not involve pre-depletion of the whole blood of red blood cells (RBC) prior to filtration and do not achieve the type of volume reduction that is needed in blood cell banking applications.